Methods, compositions, unit dosage forms, and kits for pharmacologic stress testing with reduced side effects

ABSTRACT

Methods are presented that comprise the administration of a pharmaceutical composition comprising adenosine and dipyridamole, as well methods comprising the combined administration of dipyridamole administered as a bolus with adenosine given as an infusion, both at dosages below their respective single agent dosages, for detecting the presence and/or assessing the severity of myocardial ischemia during pharmacologic stress tests. The methods are useful for exploiting the vasodilating abilities of adenosine at doses at which side effects related to adenosine are substantially reduced while optimal coronary artery perfusion is achieved. Also presented are compositions, unit dosage forms, and kits that are useful in performing the methods.

1. CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 11/772,684,filed Jul. 2, 2007, which claims the benefit under 35 U.S.C. §119(e) ofprovisional application No. 60/818,928, filed Jul. 5, 2006, the contentof all of which are incorporated herein in their entireties by referencethereto.

2. BACKGROUND

Functional assessment of myocardium, in particular the evaluation of themyocardium's oxygen status, is important in guiding therapeuticdecisions in the care of patients with cardiac ischemia. In currentclinical practice, myocardial ischemia status is most often assessedusing non-invasive nuclear perfusion imaging methodologies, such asplanar scintigraphy or single photon emission computed tomography(SPECT), with thallium and technetium as the most frequently usedisotopes. More recently, positron emission tomography (PET) withrubidium-82 has been gaining recognition as providing improved imageswith less radiation. Semi-invasive transesophageal doppler echography isalso useful to study the motion of ventricular walls, and non-invasivetransthoracic doppler echocardiography is an easy and non-invasivemethodology for measurement of coronary flow reserve.

These functional tests typically require that the patient's heart be“stressed”, either through controlled exercise or by pharmacologicmeans, and are thus generically and colloquially known as “stresstests”. Pharmacological stressors for functional assessment ofmyocardium act through coronary vasodilation: by dilating normal vesselsto a greater extent than diseased vessels, these agents establish ashunt, or “myocardial steal”, that produces differential increases inblood flow in healthy vs. diseased arteries in patients with coronaryartery disease, optimizing the discriminatory imaging of cardiac muscleareas in need of oxygen supply.

Adenosine and dipyridamole are coronary vasodilators, each of which isapproved for individual use as a pharmacologic stressor for stresstesting. Adenosine acts directly by stimulating adenosine purinergic P1receptors on the arterial wall. Dipyridamole is believed to workindirectly by blocking reuptake of adenosine at the cellular level,leading to an increase in endogenous adenosine concentration in theblood. Dipyridamole produces similar near-maximal coronary hyperemia tothat produced by exogenous adenosine, but less quickly.

To ensure near-maximal coronary vasodilation, and to provide sufficienttime for the acquisition of cardiac images, adenosine is infused for 6minutes at a dosage rate of 140 μg/kg patient body weight/min;dipyridamole is infused for 4 minutes at 140 μg/kg patient bodyweight/min. Thus, the total recommended dose of adenosine is 0.84 mg/kg,and the total recommended dose for dipyridamole is 0.56 mg/kg at theminimum and 0.80 mg/kg on average in a 4 minute infusion. Ifvasodilation is insufficient, the total dose of dipyridamole can beincreased up to 0.95 mg/kg, administered over a 6 minute infusion.

Although infused for only a few minutes, compounds that stimulateadenosine receptors are accompanied by numerous uncomfortable adverseeffects. With adenosine, the most frequently reported are flushing(44%), chest pain or chest discomfort (40%), dyspnea (28%), headache(18%), throat or neck or jaw discomfort (15%), and gastrointestinaldiscomfort (13%); other side effects are less frequent.

The adverse effects of adenosine are dose-dependent. Symptoms such asheat sensation, flushed face, dyspnea and chest pain increase asadenosine dosage is increased from 60 to 140 μg/kg/min, in a six minuteinfusion. Chest pain typically appears at doses of 90 μg/kg/min, andbecomes frequent at 120 μg/kg/min. At a dosage of 70 μg/kg/min or less,it has been noted that adenosine adverse reactions are very few and ofmild intensity. However, when administered by intravenous perfusion at70 μg/kg/min or less, or even at 90-120 μg/kg/min, adenosine showsreduced efficacy, and is not recommended for stress testing at suchreduced dosages.

The side effect profile of dipyridamole is similar, but with adverseevents occurring less often. However, dipyridamole side effects lastlonger, are more difficult to manage, and thus more frequently requirethe administration of intravenous aminophylline as an antidote.

Because dipyridamole is understood to act by increasing endogenousadenosine, use of both adenosine and dipyridamole at full intravenousdosage is contraindicated. Analogously, oral intake of dipyridamoleprior to an adenosine pharmacologic stress testing is generally avoided.

In an effort to reduce side effects at maximally effective agonistdoses, adenosinergic agents are being developed that are selective forthe A2a receptor subtype. See, e.g., U.S. Pat. Nos. 6,531,457;6,448,235; 6,322,771; and 5,877,180. Specific compounds in developmentinclude regadenoson, binodenoson and apadenoson (BMS068645). However,despite their receptor selectivity, only modest reductions in sideeffects have been observed with these compounds. In addition, thecompounds have a longer duration of action than adenosine; accordingly,the side effects, e.g., flushing, headache, and dyspnea, are longerlasting. Thus, although more specific than adenosine, these agents maybe more likely to trigger prolonged side effects, and to requireadministration of pharmacologic antidotes, than is adenosine itself,whose side effects rapidly dissipate once administration is stopped.Moreover, none of these selective agents has yet been approved forclinical use.

There thus exists a continuing need in the art for injectable agentsthat can be used for pharmacologic stress testing that have the rapidonset and short half-life of adenosine, and thus can be managedclinically in the same manner as adenosine, and that provide maximalefficacy with reduced side effects.

3. SUMMARY

Although dipyridamole is believed to act indirectly by increasingadenosine concentration, and in clinical practice has a side effectprofile similar to that of adenosine, I have now discovered thatextremely low parenteral doses of dipyridamole—on the order of 5% of thedose now used clinically in cardiac imaging studies—can potentiate thevasodilation effects of adjunctively administered adenosine withoutcommensurate potentiation of adenosine's side effects. This permitsadenosine to be used at reduced dosage to effect coronary vasodilation,e.g., for functional assessment of myocardial function, with equal orsuperior efficacy as compared to current protocols, yet with reducedside effects. Moreover, the clinical and hemodynamic effectsadvantageously stop less than one minute after cessation of adenosineadministration.

Accordingly, described herein are methods, compositions, unit dosageforms and kits that exploit this newly discovered phenomenon.

In a first aspect, methods of effecting coronary vasodilation forcardiac diagnosis are provided. The method comprises concurrentlyadministering adenosine and dipyridamole, wherein adenosine anddipyridamole are administered parenterally at an adenosine:dipyridamoleweight ratio of about 2:1 to about 10:1.

In certain embodiments of the method, the adenosine:dipyridamole ratiois about 2:1 to 4:1, such as 4:1; in various other embodiments, theadenosine:dipyridamole ratio is about 7:1 or about 8:1.

In various embodiments of the method, adenosine is administered at adosage rate of 35 to 100 μg/kg/min and dipyridamole is administered at adosage rate of 3.5-50 μg/kg/min. In some embodiments, adenosine isadministered at a dosage rate of 70 μg/kg/min and dipyridamole isadministered at a dosage rate of 10 μg/kg/min; adenosine is administeredat a dosage rate of 70 μg/kg/min and dipyridamole is administered at adosage rate of 8.75 μg/kg/min; adenosine is administered at a dosagerate of 50 μg/kg/min and dipyridamole is administered at a dosage rateof 12.5-25 μg/kg/min.

Adenosine and dipyridamole may be parenterally administered continuouslyfor a period of at least about 2 minutes, typically less than about 6minutes. In certain embodiments, adenosine and dipyridamole areparenterally administered continuously for a period of about 4 minutes.

In some embodiments of the methods presented herein, adenosine anddipyridamole are administered as a single composition. In otherembodiments, adenosine and dipyridamole are administered from separatecompositions.

In a variety of embodiments, at least one adenosine and dipyridamole isadministered by intravenous infusion. In some embodiments, at least oneadenosine and dipyridamole is administered by intra-atrial orintra-arterial administration. In some embodiments, the dosage of thatagent can be adjusted downward using a dosage multiplier of 1/200-1/400, as compared to the intravenous dosage. In embodiments in whichadenosine and/or dipyridamole is administered by intra-coronaryadministration, the dosage of that agent can be adjusted downward usinga dosage multiplier of 1/200- 1/400, as compared to the intravenousdosage.

In certain embodiments, the method usefully further comprises the stepof assessing cardiac function. Assessing cardiac function may includeuse of one or more techniques selected from the group consisting of:electrocardiography, M mode echography, two dimensional echography,three dimensional echography, echo-doppler, cardiac imaging, planar(conventional) scintigraphy, single photon emission computed tomography(SPECT), dynamic single photon emission computed tomography, positronemission tomography (PET), first pass radionuclide angiography,equilibrium radionuclide angiography, nuclear magnetic resonance (NMR)imaging, perfusion contrast echocardiography, digital subtractionangiography (DSA), and ultrafast x-ray computed tomography (CINE CT). Incertain embodiments, functional assessment is performed by SPECT; inother embodiments, the assessment is performed by PET.

In certain embodiments of the methods that further comprise assessmentof cardiac function, assessing cardiac function includes parenteraladministration of an isotope. The isotope is typically administered noless than 2.5 minutes after the concurrent parenteral administration ofadenosine and dipyridamole has begun. In some embodiments isotope can beadministered no less than 2.55 minutes, no less than 2.6 minutes, noless than 2.65 minutes, no less than 2.7 minutes, no less than 2.75minutes after the concurrent administration of adenosine anddipyridamole has begun. In some embodiments isotope can be administeredabout 2.5-2.75 minutes after the concurrent parenteral administration ofadenosine and dipyridamole has begun.

In a second aspect, methods are provided for effecting coronaryvasodilation for cardiac diagnosis. These methods comprising: (i)parenterally administering dipyridamole; and (ii) concurrently orsequentially thereafter parenterally administering an adenosine receptoragonist. Each of dipyridamole and the adenosine receptor agonist isadministered at a dosage lower than that required for maximal coronaryvasodilation when administered as a single agent by identical parenteralroute.

In some embodiments, the adenosine receptor agonist is selected from thegroup consisting of: adenosine, adenosine triphosphate (ATP), adenosinediphosphate (ADP), adenosine monophosphate (AMP), and pro-drugs andpharmaceutically acceptable salts of adenosine or AMP, ADP, ATP.

Each route of parenteral administration may be independently selectedfrom the group consisting of: intra-arterial, intravenous, and atrialadministration. In some embodiments, dipyridamole is administered byintravenous or intra-arterial bolus injection. In certain embodiments,dipyridamole is administered as an intravenous or intra-arterial bolusat a dosage of no more than 140 μg/kg, no more than 50 μg/kg, even nomore than 40 μg/kg, and typically at a dosage of at least 14 μg/kg. Forexample, in some embodiments, dipyridamole is administered as anintravenous or intra-arterial bolus at a dosage of 23 to 60 μg/kg, suchas 35 μg/kg or 40 μg/kg.

In various embodiments, dipyridamole is administered by intravenousinfusion over 1 or 2 minutes.

In some of these embodiments, the adenosine receptor agonistadministration is begun after completion of dipyridamole administration,such as between 30 seconds an 2 minutes after dipyridamole injection orinfusion.

In a variety of embodiments, dipyridamole is administered in admixturewith the adenosine receptor agonist by intravenous infusion over 2 to 6minutes, such as for 4 minutes.

In typical embodiments, the adenosine receptor agonist is adenosine,administered by intravenous infusion at a dosage rate of about 35μg/kg/min-100 μg/kg/min. In these embodiments, adenosine is administeredat a dosage rate no more than about 100 μg/kg/min. In some embodiments,adenosine is administered at a dosage rate of no more than about 70μg/kg/min, even no more than about 50 μg/kg/min. In exemplaryembodiments, the adenosine receptor agonist is adenosine, administeredby intravenous infusion at a dosage rate of at least about 35 μg/kg/min,even at least about 50 μg/kg/min. For example, in some embodiments,adenosine is administered by intravenous infusion at a rate of about 50μg/kg/min to about 70 μg/kg/min, such as about 70 μg/kg/min.

In some embodiments, dipyridamole is administered intravenously andadenosine is administered intravenously.

In certain exemplary embodiments, the adenosine receptor agonist isadenosine, the total dose of dipyridamole is 23 to 40 μg/kg, and thedosage rate for adenosine is 50 to 70 μg/kg/min. For example, in someembodiments, the total dose of dipyridamole is 40 μg/kg and the dosagerate for adenosine is 70 μg/kg/min.

The method may further comprise the step of: assessing cardiac function.In some embodiments, assessing cardiac function includes parenteraladministration of an isotope, and the isotope is administered after 2minutes, when dipyridamole and the adenosine receptor agonist areadministered sequentially, and after 2.5 minutes, after 2.55 minutes,after 2.6 minutes, after 2.65 minutes, after 2.75 minutes, after 2.8minutes, after 2.85 minutes, after 2.9 minutes or after 2.95 minutes butbefore 3 minutes, when dipyridamole and the adenosine receptor agonistare administered concurrently. In some embodiments, isotope isadministered at about 2.5-2.75 minutes after sequential administrationof dipyridamole and the adenosine receptor agonist.

In a third aspect, pharmaceutical compositions comprising adenosine anddipyridamole are presented. The compositions comprise adenosine anddipyridamole in adenosine: dipyridamole weight ratios of about 2:1 toabout 10:1, such as about 2:1 to about 4:1. In some embodiments, theratio is about 7:1 or 8:1.

In various embodiments, adenosine and dipyridamole are present inamounts that permit adenosine to be administered at a dosage rate of 35to 100 μg/kg/min and dipyridamole to be administered at a dosage rate of3.5 to 50 μg/kg/min.

The composition may be a sterile fluid, such as a sterile fluid suitablefor parenteral administration, such as intravenous administration. Insome embodiments, adenosine and dipyridamole are present atconcentrations that permit direct intravenous administration, withoutdilution.

In various embodiments, adenosine and dipyridamole are present atconcentrations that permit administration of adenosine at a dosage rateof 70 μg/kg/min and dipyridamole at a dosage rate of 8.75 to 10μg/kg/min. In some embodiments, adenosine and dipyridamole are presentat concentrations that permit administration of adenosine at a dosagerate of 50 μg/kg/min and dipyridamole at a dosage rate of 12.5 to 25μg/kg/min.

In a range of embodiments of the pharmaceutical compositions hereprovided, the concentration of adenosine is about 1 to 10 mg/ml.Usefully, the concentration of adenosine is about 3 mg/ml or 4 mg/ml,even 5 mg/ml, or 7 mg/ml.

In certain embodiments, the concentration of dipyridamole is about 0.1to 5 mg/ml, such as: 0.375 to 0.428 mg/ml; 0.5 to 0.571 mg/ml; 0.625 to0.714 mg/ml; 0.75 to 0.857 mg/ml; and 0.875 to 1 mg/ml. Theconcentration may, for example, be 1 mg/ml.

In another aspect, unit dosage forms are provided that containpharmaceutical compositions as above-described, comprising adenosine anddipyridamole.

In some embodiments, the unit dose contains about 2 to 50 ml of thepharmaceutical composition formulated as a sterile fluid, typically asterile, nonpyrogenic, solution suitable for parenteral administration.In some embodiments, the unit dose contains about 2 ml, 3 ml, 4 ml, 7ml, 8 ml or 14 ml.

In some embodiments, the unit dose contains about 5 to 60 mg ofadenosine and about 0.5 to 30 mg of dipyridamole; the composition is asolid capable of sterile reconstitution in a physiologically acceptablesolvent or solution.

In exemplary embodiments, for example, the unit dosage contains about 14mg of adenosine and about 2 mg of dipyridamole, 21 mg of adenosine andabout 3 mg of dipyridamole; about 28 mg of adenosine and about 4 mg ofdipyridamole; about 35 mg of adenosine and about 5 mg of dipyridamole;about 42 mg of adenosine and about 6 mg of dipyridamole; about 56 mg ofadenosine and about 8 mg of dipyridamole; about 20 mg of adenosine andabout 5 to 10 mg of dipyridamole; about 30 mg of adenosine and about 7.5to 15 mg of dipyridamole; about 40 mg of adenosine and about 10 to 20 mgof dipyridamole.

In a further aspect, unit doses of dipyridamole are provided. In variousembodiments, dipyridamole is provided in solution at a concentration ofabout 0.1 to 5 mg/ml.

In certain embodiments, the dipyridamole concentration is usefully about0.5 mg/ml. Among these embodiments are unit dosage forms that contain 3mg dipyridamole in 6 ml; 4 mg dipyridamole in 8 ml; 5 mg dipyridamole in10 ml; 6 mg dipyridamole in 12 ml; 8 mg dipyridamole in 16 ml. In someembodiments, the unit dose contains dipyridamole at a concentrationbetween about 3 mg/ml and about 5 mg/ml, such as 3 mg/ml or 4 mg/ml,usefully in volumes of 1 ml or of 2 ml, providing unit dosage formscontaining 6 mg dipyridamole in 2 ml and 8 mg dipyridamole in 2 ml.

In a further aspect, unit doses of adenosine are provided. The unitdoses are formulated in sterile fluid composition, and the dosepackaging permits sterile introduction of a second fluid in a volume atleast 15% that of the adenosine composition. The second fluid usefullycomprises dipyridamole.

In exemplary embodiments, the unit dose contains 21 mg adenosine in 6ml; 28 mg adenosine in 6 ml; 42 mg adenosine in 12 ml; or 56 mgadenosine in 12 ml.

In some embodiments the unit dose may comprise adenosine at aconcentration of about 4 mg/ml. In some embodiments, the unit dosecontains 28 mg adenosine in 7 ml; 56 mg adenosine in 14 ml.

Also provided are kits. The kits comprise at least one unit dose ofdipyridamole and at least one unit dose of adenosine. In someembodiments, the at least one unit dose of dipyridamole is a unit doseas above-described, and the unit dose of adenosine is a unit dose asabove-described.

4. DETAILED DESCRIPTION 4.1 Overview

Although dipyridamole is believed to act indirectly by increasingadenosine concentration, and in clinical practice has a side effectprofile similar to that of adenosine, I have now discovered thatextremely low parenteral-subclinical doses of dipyridamole—on the orderof 5% of the dose now used clinically in cardiac imaging studies—canpotentiate the vasodilation effects of adjunctively administeredadenosine without commensurate potentiation of adenosine's side effects.This permits adenosine to be used at reduced dosage to effect coronaryvasodilation, e.g., for functional assessment of myocardial function,with equal or superior efficacy as compared to current protocols, yetwith reduced side effects, of short duration.

In the first of two clinical studies reported in detail below (Example1), the hemodynamic effects of administering dipyridamole and adenosineintravenously as a combined (albeit, sequentially administered)pharmacological stressor were compared to the effects of administeringadenosine alone in 40 consecutive patients suffering from ischemic heartdisease. Each patient served as his own control. Dipyridamole wasadministered as an intravenous bolus. Adenosine was administeredimmediately thereafter by continuous intravenous infusion for threeminutes. Each of the two agents was administered at a dosage lower thanits clinically preferred dosage when used as a single agent formyocardial perfusion imaging: dipyridamole at 4-6% of its single-agenttotal dose, adenosine at one half its single-agent dosage rate.

Effects were measured using noninvasive transthoracic dopplerechocardiography (TTDE). The measured blood flow velocities (known asreflecting coronary blood flow values), whether peak or mean, were 1.5to 4% lower in absolute values than those measured upon administrationof adenosine alone at its standard dosage rate. However, thesedifferences were not statistically significant (p>0.05): there was nostatistical difference between the current standard treatment—infusionof adenosine alone at 140 μg/kg/min—and sequential bolus administrationof dipyridamole at 4-6% of its typical single-agent total dose followedby adenosine infusion at 70 μg/kg/min.

In addition, among the first series of 30 patients, three (3) patientsreceived the adenosine infusion two minutes after the dipyridamolebolus, rather than immediately thereafter, and two (2) patients wereinjected with the two agents concurrently in the same infusion lineusing a “Y” connector. No differences were seen as compared to thesequential administration protocol.

A significant reduction was seen in the incidence of chest pain amongthe 40 patients in this study, as compared to the number reporting chestpain upon administration of adenosine alone at 140 μg/kg/min. Inaddition, the severity of the three main adverse side effects—chestpain, dyspnea, and flushing—cumulated across all dipyridamole doses, wasreduced by 31.6% with the sequential combination as compared to standardadenosine treatment. This decrease was statistically significant(p=0.001).

As reported in detail in Example 2, below, 27 patients have now beenassessed in a subsequent Phase II study comparing dipyridamole-adenosinecombination administration to adenosine alone (Adenoscan®, Astellas) asthe pharmacologic stressor in coronary patients undergoing single photonemission computed tomography (SPECT) imaging studies.

Data from initial patients who participated in a preliminarydose-finding study demonstrated that either bolus intravenousadministration of dipyridamole at 35 μg/kg over 20-30 seconds, followedby intravenous infusion of adenosine at 70 μg/kg/min (tested in 3patients) or the concurrent administration of the two drugs at the samedosage (tested in 5 patients), provided images comparable to Adenoscan(adenosine at 140 μg/kg/min) in 7 consecutive patients, whileunder-scoring Adenoscan in one patient, but within the acceptable limitsdefined by the protocol. The combination stressor of 40 μg/kgdipyridamole followed by 70 μg/kg/min adenosine tested in 10 patients ortheir concurrent administration at the same dosage (adenosine 70μg/kg/min with dipyridamole 10 μg/kg/min) tested in 9 patients showedequivalent, and sometimes better results, than Adenoscan in terms ofimaging efficacy in 10 and 9 consecutive patients respectively.

Significant reduction in both the occurrence and the severity of chestpain with the dipyridamole-adenosine combination, as compared toadenosine alone, was observed, as was reduction in ST changes on EKG.

The data from these two studies demonstrate that the sequential bolusadministration of dipyridamole at 28 to 40 μg/kg—well below the totaldose infused when dipyridamole is used as a single agentstressor—followed by infusion of adenosine at 70 μg/kg/min (50% lessthan its usual dosage), is equally efficacious in providing coronaryvasodilation for imaging studies, while causing fewer side effects. Thedata also demonstrate that dipyridamole and adenosine may be combined ina single infusion, over 4 minutes, to similar effect. Among the sideeffects reduced by the combination of the present invention are chestpain, and the risk of significant heart blockage.

Accordingly, described herein are methods, pharmaceutical compositions,unit dosage forms, and kits that exploit this discovery, combiningadenosine with dipyridamole at dosages at which some of the mostfrequent side effects of both adenosine and dipyridamole, notablycardiac side effects, are significantly reduced, while maintainingoptimal coronary vasodilation for the diagnosis of myocardial ischemia.

4.2 Methods of Effecting Coronary Vasodilation

In a first aspect, methods of effecting coronary vasodilation forcardiac diagnosis are provided.

In typical embodiments, the methods comprise parenterally administeringdipyridamole and concurrently or sequentially thereafter parenterallyadministering an adenosine receptor agonist. Each of dipyridamole andthe adenosine receptor agonist is administered at a dosage lower thanthat required for maximal coronary vasodilation when the respectiveagent is administered individually by identical parenteral route.Dipyridamole and the adenosine receptor agonist are administered inamounts, at weight ratios, and for a time, sufficient to achieve thedesired therapeutic or diagnostic effect.

Programmable syringe pumps or micropumps, as are typical in clinicalpractice, are usefully employed to facilitate parenteral administrationin precise dosage.

The route of parenteral administration is chosen based upon the desiredclinical effect, as further described below. In certain embodiments, atleast one of dipyridamole and the adenosine receptor agonist isadministered by intravenous infusion. In other embodiments, at least oneof dipyridamole and the adenosine receptor agonist is administered byintra-arterial infusion, such as intra-coronary infusion, or byintra-atrial infusion. In these latter embodiments, the active isadministered at a lower rate, and at a lower dosage, than forintravenous infusion, as further described below. In yet otherembodiments, at least one of the actives is administered as a perfusate.

In some embodiments, at least one of dipyridamole and the adenosinereceptor agonist is infused over a period of time of at least 1 minute,typically at least 2 minutes, 3 minutes, 4 minutes, 5 minutes, even atleast 6 minutes. As used herein, “continuous infusion” intends infusionover a period of at least 2 minutes.

In some embodiments, dipyridamole is administered by intravenousinfusion at an infusion rate from 3.5 μg/kg/min to 50 μg/kg/min. Alldosage ranges described herein include the upper and lower recitedlimits, and nonintegral intermediary values. Thus, in some embodiments,dipyridamole is infused at a rate of at least about 3.5 μg/kg/min, atleast about 4 μg/kg/min, at least about 5 μg/kg/min, at least about 6μg/kg/min, at least about 7 μg/kg/min, at least about 7.5 μg/kg/min, atleast about 8 μg/kg/min, at least about 8.75 μg/kg/min, at least about 9μg/kg/min, at least about 10 μg/kg/min, at least about 11 μg/kg/min, atleast about 11.25 μg/kg/min, at least about 12 μg/kg/min, at least about12.5 μg/kg/min, at least about 13 μg/kg/min, at least about 13.75μg/kg/min, at least about 14 μg/kg/min, at least about 15 μg/kg/min, atleast about 16 μg/kg/min, at least about 16.25 μg/kg/min, at least about17 μg/kg/min, and at least about 17.5 μg/kg/min, at least about 18μg/kg/min, at least about 19 μg/kg/min, at least about 20 μg/kg/min, atleast about 21 μg/kg/min, at least about 22 μg/kg/min, at least about 23μg/kg/min, at least about 24 μg/kg/min, at least about 25 μg/kg/min, atleast about 26 μg/kg/min, at least about 27 μg/kg/min, at least about 28μg/kg/min, at least about 29 μg/kg/min, at least about 30 μg/kg/min, atleast about 31 μg/kg/min, at least about 32 μg/kg/min, at least about 33μg/kg/min, at least about 34 μg/kg/min, at least about 35 μg/kg/min, atleast about 36 μg/kg/min, at least about 37 μg/kg/min, at least about 38μg/kg/min, at least about 39 μg/kg/min, at least about 40 μg/kg/min, atleast about 41 μg/kg/min, at least about 42 μg/kg/min, at least about 43μg/kg/min, at least about 44 μg/kg/min, at least about 45 μg/kg/min, atleast about 46 μg/kg/min, at least about 47 μg/kg/min, at least about 48μg/kg/min, at least about 49 μg/kg/min, at least about 50 μg/kg/min,with intermediate values permissible.

In some embodiments, dipyridamole is infused intravenously at a rate ofno more than about 50 μg/kg/min, no more than about 49 μg/kg/min, nomore than about 48 μg/kg/min, no more than about 47 μg/kg/min, no morethan 46 μg/kg/min, no more than about 45 μg/kg/min, no more than about44 μg/kg/min, no more than about 43 μg/kg/min, no more than about 42μg/kg/min, no more than about 41 μg/kg/min, no more than about 40μg/kg/min, no more than about 39 μg/kg/min, no more than about 38μg/kg/min, no more than about 37 μg/kg/min, no more than about 36μg/kg/min, no more than about 35 μg/kg/min, no more than about 34μg/kg/min, no more than about 33 μg/kg/min, no more than about 32μg/kg/min, no more than about 31 μg/kg/min, no more than about 30μg/kg/min, of no more than about 29 μg/kg/min, no more than about 28μg/kg/min, no more than about 27 μg/kg/min, no more than about 26μg/kg/min, no more than about 25 μg/kg/min, no more than about 24μg/kg/min, no more than about 23 μg/kg/min, no more than about 22μg/kg/min, no more than about 21 μg/kg/min, no more than about 20μg/kg/min, no more than about 19 μg/kg/min, no more than about 18μg/kg/min, no more than about 17.5 μg/kg/min, no more than about 17μg/kg/min, no more than about 16.25 μg/kg/min, no more than about 16μg/kg/min, no more than about 15 μg/kg/min, no more than about 14μg/kg/min, no more than about 13.75 μg/kg/min, no more than about 13μg/kg/min, no more than about 12.5 μg/kg/min, no more than about 12μg/kg/min, no more than about 11.25 μg/kg/min, no more than about 11μg/kg/min, no more than about 10 μg/kg/min, no more than about 9μg/kg/min, no more than about 8.75 μg/kg/min, no more than about 8μg/kg/min, no more than about 7.5 μg/kg/min, no more than about 7μg/kg/min, no more than about 6 μg/kg/min, no more than about 5μg/kg/min, no more than about 4 μg/kg/min, no more than about 3.5μg/kg/min, with intermediate values permissible.

In some embodiments, dipyridamole is administered as a bolus, typicallyover a period of about 20-30 seconds.

In some of these embodiments, dipyridamole is administered as anintravenous bolus. In such embodiments, dipyridamole is administered ata dosage between 14 μg/kg to 140 μg/kg. In various embodiments,dipyridamole is administered intravenously as a bolus at a dosagebetween 28 μg/kg and 40 μg/kg.

Thus, in certain embodiments, dipyridamole is administered as anintravenous bolus at a dose of at least about 14 μg/kg, at least about20 μg/kg, at least about 25 μg/kg, at least about 28 μg/kg, at leastabout 29 μg/kg, at least about 30 μg/kg, at least about 31 μg/kg, atleast about 32 μg/kg, at least about 33 μg/kg, at least about 34 μg/kg,at least about 35 μg/kg, at least about 36 μg/kg, at least about 37μg/kg, at least about 38 μg/kg, at least about 39 μg/kg, at least about40 μg/kg, at least about 45 μg/kg, at least about 50 μg/kg, at leastabout 55 μg/kg, at least about 60 μg/kg, at least about 65 μg/kg, evenat least about 70, 80, 90, 100, 110, 120, 130, even 140 μg/kg, withintermediate doses permissible.

In some embodiments, dipyridamole is administered intravenously as abolus at a dosage of no more than about 140 μg/kg, 130 μg/kg, 120 μg/kg,110 μg/kg, 100 μg/kg, 90 μg/kg, 80 μg/kg, 70 μg/kg, even no more thanabout 60 μg/kg, even no more than about 55 μg/kg, no more than about 50μg/kg, no more than about 45 μg/kg, no more than about 40 μg/kg, no morethan about 39 μg/kg, no more than about 38 μg/kg, no more than about 37μg/kg, no more than about 36 μg/kg, no more than about 35 μg/kg, no morethan about 34 μg/kg, no more than about 33 μg/kg, no more than about 32μg/kg, no more than about 31 μg/kg, no more than about 30 μg/kg, no morethan about 29 μg/kg, no more than about 28 μg/kg, no more than about 25μg/kg/, no more than about 20 μg/kg/, no more than about 14 μg/kg, withintermediate values permissible.

When administered to a human being, the dosages of dipyridamole usefulin the methods of the present invention can be expressed in μg bymultiplying the dosage, expressed as μg/kg, by the weight of theindividual. For example, for a human weighing 50 kg, the dosage ofdipyridamole useful in the present methods can be expressed as rangingbetween 700 to 7,000 μg; for a human being weighing 60 kg, the dosage ofdipyridamole can be expressed as ranging between 840 to 8,400 μg; for ahuman being weighing 75 kg, the dosage of dipyridamole can be expressedas ranging between 1,050 to 10,500 μg; and for a human being weighing100 kg, the dosage can be expressed as ranging between 1,400 to 14,000μg.

In various embodiments, dipyridamole is infused intra-arterially at aninfusion rate of no more than about 0.07 μg/kg/min, no more than about0.06 μg/kg/min, no more than about 0.05 μg/kg/min, no more than about0.04 μg/kg/min, no more than about 0.03 μg/kg/min, no more than about0.02 μg/kg/min, or no more than about 0.01 μg/kg/min, with intermediatevalues permissible.

In various embodiments, the adenosine receptor agonist is selected fromthe group consisting of adenosine, and adenosine donors (that is,compounds that can be metabolized to adenosine), including naturaldonors such as adenosine triphosphate (ATP), adenosine diphosphate(ADP), and adenosine monophosphate (AMP), each at approximately the samedosages as adenosine, and any synthetic molecule that is capable ofbeing metabolized to adenosine, and pharmaceutically acceptable saltsthereof.

Typically, adenosine is used. For convenience, its particular use willhereafter be described, without intending thereby to limit the describedmethods to use of adenosine as the adenosine receptor agonist.

In some embodiments, adenosine is administered by intravenous infusionat an infusion rate between 35 μg/kg/min to 100 μg/kg/min. Thus, in someembodiments, adenosine is infused at a rate of at least about 35μg/kg/min, at least about 40 μg/kg/min, at least about 45 μg/kg/min, atleast about 50 μg/kg/min, at least about 55 μg/kg/min, at least about 60μg/kg/min, at least about 65 μg/kg/min, at least about 70 μg/kg/min, atleast about 75 μg/kg/min, at least about 80 μg/kg/min, at least about 85μg/kg/min, at least about 90 μg/kg/min, at least about 95 μg/kg/min, andat least about 100 μg/kg/min, with intermediate values permissible.

In various embodiments, adenosine is infused intravenously at a rate ofno more than about 100 μg/kg/min, no more than about 95 μg/kg/min, nomore than about 90 μg/kg/min, no more than about 85 μg/kg/min, no morethan about 80 μg/kg/min, no more than about 75 μg/kg/min, no more thanabout 70 μg/kg/min, no more than about 65 μg/kg/min, no more than about60 μg/kg/min, no more than about 55 μg/kg/min, no more than about 50μg/kg/min, no more than about 45 μg/kg/min, no more than about 40μg/kg/min, no more than about 35 μg/kg/min, with intermediate valuespermissible.

When administered to a human being, the dosage rate of adenosine can beexpressed in μg/min by multiplying the dosage rate expressed inμg/kg/min by the weight of the individual. For example, for a humanbeing weighing 50 kg, the dosage of adenosine useful in the practice ofthe present methods can be expressed as ranging between 1,750 to 5,000μg/min; for a human being weighing 60 kg, the dosage rate of adenosinecan be expressed as ranging between 2,100 to 6,000 μg/min; for a humanbeing weighing 75 kg, the dosage of adenosine can be expressed asranging between 2,625 to 7,500 μg/min; and for a human being weighing100 kg, the dosage of adenosine can be expressed as ranging between3,500 to 10,000 μg/min.

In some embodiments, adenosine is administered by intra-arterialinfusion, such as intracoronary infusion, at an infusion rate about 200-to 400-fold lower than intravenous infusion. Thus, in some embodiments,adenosine is infused at a rate of at least about 0.50 μg/kg/min, atleast about 0.45 μg/kg/min, at least about 0.40 μg/kg/min, 0.35μg/kg/min, at least about 0.30 μg/kg/min, at least about 0.25 μg/kg/minat least about 0.20 μg/kg/min, at least about 0.15 μg/kg/min, at leastabout 0.10 μg/kg/min, with intermediate values permissible.

In various embodiments, adenosine is infused intra-arterially and inparticular intracoronarily at an infusion rate of no more than about0.10 μg/kg/min, no more than about 0.15 μg/kg/min, no more than about0.20 μg/kg/min, no more than about 0.25 μg/kg/min, no more than about0.30 μg/kg/min, no more than about 0.35 μg/kg/min, no more than about0.40 μg/kg/min, no more than about 0.45 μg/kg/min, even no more thanabout 0.50 μg/kg/min, with intermediate values permissible.

In various embodiments, the methods presented herein compriseparenterally administering dipyridamole; and concurrently orsequentially thereafter parenterally administering an adenosine receptoragonist, such as adenosine, at an adenosine:dipyridamole (A:D) weightratio of about 2:1 to about 10:1. In various embodiments, the methodscomprise concurrently administering adenosine and dipyridamole at anadenosine:dipyridamole ratio of about 2:1 to about 10:1.

In some embodiments, the ratio is about 2:1, 3:1, 4:1, 5:1, 6:1, 7:1,8:1, 9:1, even 10:1, with nonintegral ratios between 2:1 and 10:1permissible. In certain embodiments, the methods comprise concurrentinfusion of adenosine and dipyridamole at an A:D ratio of about 6:1 to8:1, preferably about 7:1. For certain methods further described below,embodiments usefully comprise concurrent parenteral infusion ofadenosine and dipyridamole at an A:D weight ratio of about 2:1 to 4:1.

In some embodiments, dipyridamole is administered by intra-coronaryinfusion: in such embodiments, dipyridamole is typically administered atan infusion rate which is about 1/7 that of adenosine, and between 0.01to 0.07 μg/kg/min. Thus, in some embodiments, dipyridamole is infusedintra-arterially at a rate of at least about 0.01 μg/kg/min, at leastabout 0.02 μg/kg/min at least about 0.03 μg/kg/min at least about 0.04μg/kg/min at least about 0.05 μg/kg/min at least about 0.06 μg/kg/min atleast about 0.07 μg/kg/min.

In various embodiments, dipyridamole is administered as an intravenousbolus, and adenosine is administered thereafter as an intravenousinfusion.

In certain such embodiments, dipyridamole is administered over about20-30 seconds, and adenosine is thereafter infused for about 2 to 6minutes.

In these embodiments, the total dose of dipyridamole given intravenouslyas a bolus is typically between 1/16 to 1/24, e.g., 1/20 (5%), that ofthe total recommended standard dose when dipyridamole is used as asingle agent (standard single agent dose: 0.56 mg-0.80 mg/kg). In theseembodiments, the total dose of intravenously infused adenosine istypically 25% to 50% that of the total recommended standard dose whenadenosine is used as a single agent (standard single agent dose: 0.84mg/kg).

In typical embodiments, dipyridamole is administered as an IV bolus over20-30 seconds at a dosage of 14 to 60 μg/kg, followed immediately (thatis, as soon as clinically practicable, typically within about 5 to 30seconds) by the infusion of adenosine at a dosage of 35 to 100 μg/kg/minfor a period of 3 to 6 minutes. The duration of adenosine administrationis determined by the chosen imaging methodology, as is well known in theart.

In some embodiments, an intravenous dipyridamole bolus of 28-40 μg/kg isfollowed immediately—that is, as soon as clinically practicable,typically within about 5 to 30 seconds—by intravenous infusion ofadenosine at 50-70 μg/kg/min for 2 to 6 minutes. In certain embodiments,an IV dipyridamole bolus of 40 μg/kg is followed immediately byintravenous administration of adenosine at 70 μg/kg/min for 4 minutes.

In sequential administration embodiments, adenosine infusion may bedelayed as long as 2-10 minutes after dipyridamole bolus, typically nomore than 5 minutes after dipyridamole bolus.

In sequential administration embodiments, dipyridamole may be injectedmanually as a bolus via a syringe, although programmable administration(e.g., by micropump) is also possible. When administered by micropump,dipyridamole may be injected over 1 or to 2 minutes prior to adenosineinfusion. Adenosine infusion is typically accomplished using aprogrammable device so as to ensure its measured delivery.

In some embodiments, dipyridamole and adenosine are administeredconcurrently.

In certain concurrent administration embodiments, dipyridamole andadenosine are in separate unit dosage forms, and are mixed prior toadministration and infused together in a single composition.

For example, in some embodiments, a volume of dipyridamole correspondingto a dosage of 14 to 60 μg/kg is sampled and a volume of adenosinecorresponding to a dosage of 35 to 100 μg/kg/min is similarly sampledand the two mixed in the same syringe. The mixture is then infused over3 to 6 minutes. The duration of intravenous administration is determinedby the chosen imaging methodology, as is well known in the art.

In some embodiments, a volume of dipyridamole corresponding to 28-40μg/kg is sampled and a volume of adenosine corresponding to a dosage of50 to 70 μg/kg/min is similarly sampled, and the two mixed in the samesyringe. The mixture is then infused over 3 to 6 minutes. In certainembodiments, a volume of dipyridamole corresponding to 40 μg/kg issampled and a volume of adenosine corresponding to a dosage of 70μg/kg/min is similarly sampled and the two mixed in the same syringe.The mixture is then infused over 4 minutes. Thus, as is describedfurther below, in another aspect, specific unit dosage forms ofadenosine are provided, usefully copackaged with specific unit dosageforms of dipyridamole, so as to facilitate the sequential sampling andmixture of both actives in the same syringe.

In other embodiments, the total volume of the dipyridamole unit dosageform is injected into the adenosine vial and the two are mixed. Thus, asdescribed below, in another aspect the invention provides unit dosageforms of adenosine packaged so as to permit the sterile introduction ofan appropriate volume of dipyridamole.

In embodiments in which the two actives are in admixture in a singlecomposition prior to administration, the volume to administer isusefully calculated using adenosine dose tables as reference.

In other embodiments, dipyridamole and adenosine are concurrentlyadministered from separate compositions. Usefully, the two agents may beintroduced into the same infusion line using a Y connector (at the samedosages as set forth above).

4.3 Methods of Pharmacological Stress Testing

Vasodilation that is achieved according to the above-described methodswill often be used as a pharmacological stressor in cardiac stresstests. Accordingly, in certain embodiments, the methods further comprisethe step of assessing cardiac function.

Any method suitable for assessing cardiac function in cardiac stresstesting may be used.

In various embodiments, for example, assessing cardiac function includesuse of one or more techniques selected from the group consisting of:electrocardiography, echography (M mode, two-dimensional, and threedimensional), echo-doppler, cardiac imaging, including planar(conventional) scintigraphy, single photon emission computed tomography(SPECT), dynamic single photon emission computed tomography (D-SPECT™Cardiac Scan), positron emission tomography (PET), radionuclideangiography (first pass and equilibrium studies utilizing, e.g.,technetium-99m-labeled red blood cells), nuclear magnetic resonance(NMR) imaging, perfusion contrast echocardiography, digital subtractionangiography (DSA), and ultrafast x-ray computed tomography (ONE CT).

SPECT and PET Present Certain Advantages.

SPECT studies can be performed using any of the isotopes known to besuitable for such studies, such as thallium-201, technetium sestamibi,tetrofosmine. PET studies can be performed using any of the isotopesknown to be suitable for such studies, such as for example rubidium-82,nitrogen-13, fluorine-18, carbon-11, boron-11, and oxygen-15.

Typically, isotope is injected during the infusion of adenosine, andimaging begins after the end of the infusion. In some embodiments, theisotope is administered no less than about 2.5 minutes after adenosineinfusion has begun.

4.4 Pharmaceutical Compositions

In another aspect, pharmaceutical compositions that are useful in theabove-described methods are provided.

In typical embodiments, the pharmaceutical composition comprisesadenosine and dipyridamole in an adenosine:dipyridamole (A:D) weightratio of about 2:1 to about 10:1, with intermediate (includingnonintegral) values permissible. In certain embodiments in whichadenosine is intended to be administered at 70 μg/kg/min, the ratio isusefully about 7:1, 8:1, 9:1 and 10:1, with intermediate and nonintegralratios permissible. In other embodiments, in which adenosine is to beadministered at 50 μg/kg/min or less, A:D ratios are usefully about 2:1,3:1, and 4:1, with intermediate and nonintegral ratios between 2:1 and4:1 permissible. For certain clinical methods, the composition usefullycomprises adenosine and inosine at an A:D weight ratio of about 7:1.

In certain embodiments, the pharmaceutical composition is suitable forintravenous, intra-atrial, or intra-arterial infusion.

The composition may, for example, be in the form of a sterile,nonpyrogenic, fluid composition.

In typical fluid embodiments, the concentration of adenosine is at leastabout 1 mg/ml, 2 mg/ml, 3 mg/ml, 4 mg/ml and possibly 5 mg/ml, withintermediate, nonintegral, values permissible. These embodimentstypically have a pH of about 3.5 to about 8. In other typical fluidembodiments with readily a lower pH (e.g., pH 2-3.5), adenosineconcentration can be higher, even at least about 5 mg/ml, 6 mg/ml, 7mg/ml, 8 mg/ml, 9 mg/ml and even 10 mg/ml, with intermediate,nonintegral, values permissible. In typical pharmaceutical compositionembodiments, adenosine is present at a concentration of about 3 mg/ml, 4mg/ml, 5 mg/ml, or 7 mg/ml.

In various fluid embodiments, the concentration of dipyridamole is atleast about 0.1 mg/ml, and may usefully be as high as 2.5 mg/ml, andeven 5 mg/ml. The concentration may, in certain embodiments, be at leastabout 0.1 mg/ml, 0.2 mg/ml, 0.3 mg/ml, 0.4 mg/ml, 0.5 mg/ml, 0.6 mg/ml,0.7 mg/ml, 0.8 mg/ml, 0.9 mg/ml, 1 mg/ml, or more, including, e.g., 1.1mg/ml, 1.2 mg/ml, 1.3 mg/ml, 1.4 mg/ml, 1.5 mg/ml, 1.6 mg/ml, 1.7 mg/ml,1.8 mg/ml, 1.9 mg/ml, 2 mg/ml, 2.1 mg/ml, 2.2 mg/ml, 2.3 mg/ml, or 2.4mg/ml, 2.5 mg/ml, 3 mg/ml, 3.5 mg/ml, 4 mg/ml, 4.5 mg/ml, 5 mg/ml, withintermediate and nonintegral values permissible (e.g., 0.43, 0.57, 0.71or 0.86 mg/ml).

In certain embodiments, the composition comprises adenosine at aconcentration of about 3 mg/ml, and dipyridamole at a concentration ofabout 0.375-0.428 mg/ml (A:D ratios of 8:1 and 7:1), which may berounded to 0.38-0.43 mg/ml. In one embodiment, for example, thecomposition comprises adenosine at a concentration of about 3 mg/ml anddipyridamole at a concentration of about 0.43 mg/ml (ratio 7:1). Inanother embodiment, the composition comprises adenosine at aconcentration of about 4 mg/ml and dipyridamole at a concentration ofabout 0.5-0.57 mg/ml (ratios of about 8:1 to 7:1). In anotherembodiment, the composition comprises adenosine at a concentration ofabout 5 mg/ml and dipyridamole at a concentration of about 0.62-0.71mg/ml (ratios of 8:1 and 7:1). In another embodiment the compositioncomprises adenosine at a concentration of about 6 mg/ml and dipyridamoleat a concentration of about 0.86 mg/ml (ratio 7:1). In anotherembodiment, the composition comprises adenosine at a concentration ofabout 7 mg/ml and dipyridamole at a concentration of about 1 mg/ml(ratio 7:1), and so on, up to adenosine concentrations as high as 10mg/ml.

In other embodiments, the composition is dry, and suitable forreconstitution prior to infusion by addition of a sterile fluid intowhich both dipyridamole and adenosine are readily solubilized. Usefully,the composition comprises adenosine and dipyridamole in amounts suitableto permit reconstitution in the enclosing vessel to the adenosine anddipyridamole concentrations above-described.

Whether fluid or dry, the pharmaceutical composition may furthercomprise carriers and excipients suitable for intravenous, intra-atrial,or intra-arterial administration, as are well known in the art. Amongsuch excipients are those used in currently approved dipyridamole andadenosine compositions, such as tartaric acid, hydrochloric acid andpolyethylene glycol (macrogol 600). Others are permissible, such as, forexample, mannitol. See, http://www.adenosin.com/en/en_SPC_(—)05.pdf(Item Development AB, 2005), incorporated herein by reference. See also,Remington: The Science and Practice of Pharmacy, 21^(st) ed. (2005),Lippincott Williams & Wilkins (ISBN: 0781746736), incorporated herein byreference.

The compositions may further comprise additional actives, and in someembodiments, may further comprise contrast agents, including ultrasoundand MRI contrast agents.

In embodiments intended for continuous intravenous infusion in themethods above-described, adenosine is typically present in thepharmaceutical composition at a concentration, or in a weight amount,that permits adenosine to be infused at a rate between about 35μg/kg/min to about 100 μg/kg/min.

In some of these embodiments, adenosine is present in an amount thatpermits infusion at a rate of at least about 35 μg/kg/min, at leastabout 40 μg/kg/min, at least about 45 μg/kg/min, at least about 50μg/kg/min, at least about 55 μg/kg/min, at least about 60 μg/kg/min, atleast about 65 μg/kg/min, at least about 70 μg/kg/min, at least about 75μg/kg/min, at least about 80 μg/kg/min, at least about 85 μg/kg/min, atleast about 90 μg/kg/min, at least about 95 μg/kg/min, and at leastabout 100 μg/kg/min, with intermediate and nonintegral valuespermissible.

In some embodiments, adenosine is present in the composition in anamount that permits infusion at a rate of no more than about 100μg/kg/min, no more than about 95 μg/kg/min, no more than about 90μg/kg/min, no more than about 85 μg/kg/min, no more than about 80μg/kg/min, no more than about 75 μg/kg/min, no more than about 70μg/kg/min, no more than about 65 μg/kg/min, no more than about 60μg/kg/min, no more than about 55 μg/kg/min, no more than about 50μg/kg/min, no more than about 45 μg/kg/min, no more than about 40μg/kg/min, no more than about 35 μg/kg/min, with intermediate andnonintegral values permissible.

In embodiments intended for continuous intravenous infusion,dipyridamole is typically present in the pharmaceutical composition at aconcentration, or in a weight amount, that permits dipyridamole to beinfused at a rate between about 3.5 μg/kg/min to 50 μg/kg/min.

In some of these embodiments, dipyridamole is present in an amount thatpermits infusion at a rate of at least about 3.5 μg/kg/min, at leastabout 4 μg/kg/min, at least about 5 μg/kg/min, at least about 6μg/kg/min, at least about 7 μg/kg/min, at least about 7.5 μg/kg/min, atleast about 8 μg/kg/min, at least about 8.75 μg/kg/min, at least about 9μg/kg/min, at least about 9.25 μg/kg/min, at least about 9.50 μg/kg/minat least about 10 μg/kg/min, at least about 11 μg/kg/min, at least about11.25 μg/kg/min, at least about 12 μg/kg/min, at least about 12.5μg/kg/min, at least about 13 μg/kg/min, at least about 13.75 μg/kg/min,at least about 14 μg/kg/min, at least about 15 μg/kg/min, at least about16 μg/kg/min, at least about 16.25 μg/kg/min, at least about 17μg/kg/min, and at least about 17.5 μg/kg/min, at least about 18μg/kg/min, at least about 19 μg/kg/min, at least about 20 μg/kg/min, atleast about 21 μg/kg/min, at least about 22 μg/kg/min, at least about 23μg/kg/min, at least about 24 μg/kg/min, at least about 25 μg/kg/min, atleast about 26 μg/kg/min, at least about 27 μg/kg/min, at least about 28μg/kg/min, at least about 29 μg/kg/min, at least about 30 μg/kg/min, atleast about 31 μg/kg/min, at least about 32 μg/kg/min, at least about 33μg/kg/min, at least about 34 μg/kg/min, at least about 35 μg/kg/min, atleast about 36 μg/kg/min, at least about 37 μg/kg/min, at least about 38μg/kg/min, at least about 39 μg/kg/min, at least about 40 μg/kg/min, atleast about 41 μg/kg/min, at least about 42 μg/kg/min, at least about 43μg/kg/min, at least about 44 μg/kg/min, at least about 45 μg/kg/min, atleast about 46 μg/kg/min, at least about 47 μg/kg/min, at least about 48μg/kg/min, at least about 49 μg/kg/min, at least about 50 μg/kg/min,with intermediate and nonintegral values permissible.

In some embodiments, dipyridamole is present in the composition in anamount that permits intravenous infusion at a rate of no more than about50 μg/kg/min, no more than about 49 μg/kg/min, no more than about 48μg/kg/min, no more than about 47 μg/kg/min, no more than about 45μg/kg/min, no more than about 44 μg/kg/min, no more than about 43μg/kg/min, no more than about 42 μg/kg/min, no more than about 41μg/kg/min, no more than about 40 μg/kg/min, no more than about 39μg/kg/min, no more than about 38 μg/kg/min, no more than about 37μg/kg/min, no more than about 36 μg/kg/min, no more than about 35μg/kg/min, no more than about 34 μg/kg/min, no more than about 33μg/kg/min, no more than about 32 μg/kg/min, no more than about 31μg/kg/min, no more than about 30 μg/kg/min, of no more than about 29μg/kg/min, no more than about 28 μg/kg/min, no more than about 27μg/kg/min, no more than about 26 μg/kg/min, no more than about 25μg/kg/min, no more than about 24 μg/kg/min, no more than about 23μg/kg/min, no more than about 22 μg/kg/min, no more than about 21μg/kg/min, no more than about 20 μg/kg/min, no more than about 19μg/kg/min, no more than about 18 μg/kg/min, no more than about 17.5μg/kg/min, no more than about 17 μg/kg/min, no more than about 16.25μg/kg/min, no more than about 16 μg/kg/min, no more than about 15μg/kg/min, no more than about 14 μg/kg/min, no more than about 13.75μg/kg/min, no more than about 13 μg/kg/min, no more than about 12.5μg/kg/min, no more than about 12 μg/kg/min, no more than about 11.25μg/kg/min, no more than about 11 μg/kg/min, no more than about 10μg/kg/min, no more than about 9.25 μg/kg/min, no more than about 9.50μg/kg/min no more than about 9 μg/kg/min, no more than about 8.75μg/kg/min, no more than about 8 μg/kg/min, no more than about 7.5μg/kg/min, no more than about 7 μg/kg/min, no more than about 6μg/kg/min, no more than about 5 μg/kg/min, no more than about 4μg/kg/min, no more than about 3.5 μg/kg/min, with intermediate andnonintegral values permissible

4.5 Unit Dosage Forms

4.5.1 Dipyridamole: Adenosine Combined Compositions

The pharmaceutical compositions described herein are usefully packagedin a unit dosage form adapted for use in the methods above-described.

In embodiments in which the pharmaceutical composition is in the form ofa liquid suitable for parenteral infusion, the composition may, forexample, be packaged in volumes of 2-50 ml. Convenient unit dosage formscontain 2 to 14 ml, typically 2, 3, 4, 5, 6, 7, 8, or 14 ml. Unit dosageforms containing volumes as low as 1 ml, and unit dosage formscontaining higher volumes, such as 15 or 20 ml, are also possible.Intermediate and nonintegral volumes are permissible.

Table 1 below lists certain useful unit dosage form embodiments of theadenosine: dipyridamole pharmaceutical compositions herein described.

TABLE 1 Total Maximal amount of Adenosine Total amount of patientdipyridamole concentration Volume adenosine per weight (A:D ratio 7:1)(mg/ml) (ml) dosage unit (mg) (kgs) (mg) 3 7 21 75 3 14 42 150 6 4 7 28100 4 14 56 200 8 5 7 35 125 5 6 7 42 150 6 7 2 14 50 2 3 21 75 3 4 28100 4 5 35 125 5 6 42 150 6 8 56 200 8

Thus, in some embodiments, the unit dosage form usefully contains 14 mgof adenosine and 2 mg of dipyridamole in 2 ml; 21 mg of adenosine and 3mg of dipyridamole in 3 or 7 ml; 28 mg of adenosine and 4 mg ofdipyridamole in 4 or 7 ml; 35 mg of adenosine and 5 mg of dipyridamolein 5 or 7 ml; 42 mg of adenosine and 6 mg of dipyridamole in 6 or 7 ml;56 mg of adenosine and 8 mg of dipyridamole in 8 or 14 ml.

Various embodiments usefully package 9 mg or 12 mg adenosinerespectively in 3 ml or 4 ml for light weight patients (e.g., children).Other embodiments usefully package 20 mg adenosine in 5 ml total volume(20 mg/5 ml), 24 mg in 6 ml total volume (24 mg/6 ml), and 25 mg in 5 mltotal volume (25 mg/5 ml). Various unit dose embodiments of thepharmaceutical compositions described herein contain 30 mg adenosine ina total volume of 6 ml (30 mg/6 ml), 30 mg/10 ml, or 32 mg/8 ml. Otherunit dose embodiments usefully contain adenosine at 36 mg/9 ml, 40 mg/10ml, 40 mg/8 ml, 44 mg/11 ml, 45 mg/15 ml and 50 mg/10 ml.

In certain embodiments, the unit dosage form contains, in a total of 10ml, 30 mg of adenosine and 3 to 5 mg of dipyridamole, with intermediateand nonintegral amounts of dipyridamole permissible (e.g., 3.75 mg or4.28 mg, for A:D ratios of 8:1 and 7:1). In other embodiments, a 6 mlvial or ampule contains 24 mg of adenosine with 3 mg of dipyridamole(ratio 8:1). In other embodiments, an 8 ml vial or ampule will usefullycontain 32 mg of adenosine with 3.2 to 5.3 mg of dipyridamole, withintermediate and nonintegral amounts of dipyridamole permissible (e.g.,4 mg to 4.57 mg, for ratios of 8:1 and 7:1).

The container for unit dosage embodiments is typically adapted for usewith standard intravenous infusion sets.

In other embodiments, the unit dosage form contains adenosine anddipyridamole as solids suitable for reconstitution.

Whether liquid or dry, the unit dosage form is typically sterile andnonpyrogenic.

4.5.2 Dipyridamole Unit Dosage Forms

In typical embodiments of the methods herein described, dipyridamole isadministered at about 5% of the dose at which it is currentlyadministered as a single agent. Accordingly, in another aspect, theinvention provides novel unit dosage forms of dipyridamole.

Convenient unit dosage forms of dipyridamole (as single active) arevials, ampules, or prefilled syringes, usefully with 0.1 ml graduations,containing dipyridamole at a concentration of 0.5 mg/ml. At adipyridamole dose of 35-40 μg/kg, a 5 mg/10 ml vial, ampule, orprefilled syringe is sufficient for almost all clinical needs, and isconvenient for immediate and accurate dose adjustment. Also useful areunit dose forms of dipyridamole containing 4 mg/8 ml; 3.5 mg/7 ml; 3mg/6 ml; 5 mg/10 ml; 6 mg/12 ml and 8 mg/16 ml.

Unit dosage forms containing dipyridamole at a concentration of 1mg/ml—for example, unit dosage forms containing 6 mg dipyridamole in 6ml, 5 mg/5 ml, 4 mg/4 ml, 3 mg/3 ml—also find use, but fine tuning thedose may be more difficult at this higher concentration. In theseembodiments, adjustment is optimally obtained after dilution ofdipyridamole, e.g., in saline solution.

Preparations with dipyridamole concentrations over 1 mg/ml, such as 2mg/ml, 2.5 mg/ml, 3 mg/ml, 3.5 mg/ml, 4 mg/ml, 4.5 mg/ml, even 5 mg/mlare feasible, and are particularly convenient if it is intended to mixthe whole of the dipyridamole unit dose into the adenosine unit dose,prior to administration. In this case, the 2 mg/ml, 3 mg/ml, 4 mg/ml, 5mg/ml, 6 mg/2 ml or 8 mg/2 ml unit dosage forms (or prefilled syringes)are particularly useful.

In other embodiments, dipyridamole unit dosage forms containdipyridamole at a lower concentration, such as 0.1 mg/ml. Usefully, suchunit dosage forms contain 6 mg dipyridamole in 60 ml (6 mg/60 ml), 5mg/50 ml, 4 mg/40 ml, and 3 mg/30 ml. Dipyridamole preparations at aconcentration of 0.2, 0.3, and 0.4 mg/ml are also permissible.

4.5.3 Adenosine Unit Dosage Forms

As described above, in some embodiments, dipyridamole and adenosine areusefully provided in separate pharmaceutical compositions, and thencombined prior to administration. In some of these embodiments, adipyridamole composition is usefully introduced into a unit dose ofadenosine, and the combined composition then administered.

Thus, unit dosage forms of adenosine are provided, in which adenosine isformulated in sterile fluid composition, and in which the dose packagingpermits sterile introduction of a second fluid in a volume at least 15%that of the adenosine composition.

Adenosine may be present at any of the concentrations at which it ispresent in the pharmaceutical compositions above-described—e.g.,usefully from 1 mg/ml to 5 mg/ml—either as directly packaged, or asthereafter will achieved upon introduction of an appropriate amount ofdipyridamole composition.

For example, in one embodiment, an adenosine unit dosage form contains21 mg adenosine in 6 ml (21 mg/6 ml). This will reconstitute to adesired 21 mg adenosine/7 ml (3 mg/ml adenosine) composition uponintroduction of 1 ml of 3 mg/ml dipyridamole (e.g., the entirety of aunit dose of dipyridamole containing 1 ml dipyridamole at 3 mg/ml). Inanother embodiment, an adenosine unit dosage form contains 42 mg/12 ml.This will reconstitute to a desired 42 mg/14 ml (3 mg/ml) adenosine uponintroduction of a 6 mg/2 ml dipyridamole unit dose. In anotherembodiment, the adenosine unit dosage form contains 28 mg adenosine/6ml, which will reconstitute to 28 mg/7 ml (4 mg/ml adenosine) uponintroduction of a 4 mg/ml dipyridamole unit dose. In another embodiment,the adenosine unit dosage form contains 56 mg adenosine/12 ml, whichwill reconstitute to 56 mg/14 ml (4 mg/ml adenosine) upon introductionof an 8 mg/2 ml dipyridamole unit dose. In another embodiment, theadenosine unit dosage form contains 28 mg/3 ml or 35 mg/4 ml which willreconstitute to 28 mg/4 ml and 35 mg/5 ml upon introduction of a 4 or 5mg/ml dipyridamole unit dose respectively (7 mg/ml adenosine). Inanother embodiment, the adenosine unit dosage form contains 42 mg/4 mlor 56 mg/6 ml which will reconstitute to 42 mg/6 ml and 56 mg/8 ml uponintroduction of a 6 mg/2 ml or 8 mg/2 ml dipyridamole unit doserespectively (7 mg/ml adenosine). The following table summarizesexemplary unit dosage forms.

TABLE 2 Volume (ml) Maximal of Final Total Total amount patient'sInitial dipyridamole adenosine amount of of weight adenosine solutionvial (ml) Final adenosine dipyridamole covered by vial added to eachvolume after adenosine per unit (A:D ratio the volume adenosine additionof concentration dosage 7:1) composition (ml) vial dipyridamole (mg/ml)form (mg) (mg) (kgs) 6 1 7 3 21 3 75 12 2 14 3 42 6 150 6 1 7 4 28 4 10012 2 14 4 56 8 200 3 1 4 7 28 4 100 4 1 5 7 35 5 125 4 2 6 7 42 6 150 62 8 7 56 8 200

In certain embodiments, dipyridamole and adenosine are sequentiallysampled from separate unit dosage forms, and mixed in the same syringe.In these embodiments, convenient adenosine unit dosage forms are 28 mgof adenosine in 7 ml and 56 mg of adenosine in 14 ml (4 mg/mladenosine).

Typically, dosing and sampling are thereafter determined according toadenosine tables, and not dipyridamole tables.

4.6 Kits

In another aspect, kits are provided in which one or more unit doses ofdipyridamole, such as those above-described, are packaged with one ormore unit doses of adenosine, such as those above-described. Typically,the kit will comprise an equal number of dipyridamole and adenosinedoses.

In some embodiments, the unit dose of dipyridamole is packaged in apre-packed syringe, and the adenosine unit dose is packaged as a vialwith an injection port, such as a septum, permitting sterileintroduction of dipyridamole into the adenosine dose.

In various embodiments, the kit further includes one or more of anadenosine dosage table, one or more needles, diluent, and infusion sets.

5. EXAMPLES 5.1 Example 1

The effects of administering dipyridamole and adenosine intravenously asa combined (albeit, sequentially administered) pharmacological stressorwere compared to the effects of administering adenosine alone in 40consecutive patients suffering from ischemic heart disease. In thecombined administration, each of the two agents was administered at adosage lower than its clinically preferred dosage when used as a singleagent for myocardial perfusion imaging. Effects were measured usingnoninvasive transthoracic doppler echocardiography (TTDE).

Primary efficacy end-points were peak and mean diastolic flow velocities(measured as reflecting coronary blood flow values). The secondaryend-point was patient tolerance to the procedure. The protocol wasdesigned as follows.

Forty (40) consecutive patients suffering from ischemic heart diseasewere enrolled. Each patient served as his own control.

Adenosine was administered by IV infusion for three minutes at thestandard single-agent infusion rate of 140 μg/kg/min.

After a stabilization period of five minutes, patients then received anIV injection of dipyridamole at a total dose of either 23 μg/kg, 28μg/kg, or 35 μg/kg, administered as a bolus over about 20-30 seconds.These total doses are between about 4-6% of the lowest single-agenttotal dose of dipyridamole (i.e., 0.56 mg/kg, infused over a total of 4minutes).

The bolus injection of dipyridamole was followed immediately by an IVinfusion of adenosine at 70 μg/kg/min for 3 minutes. This dose is halfthe standard single-agent dosage rate of 140 μg/kg/min.

Blood flow velocity was measured in the left anterior descendingcoronary artery (LAD) at four time points: (i) before initial adenosineinfusion (spontaneous flow at rest), (ii) during the initial 140μg/kg/min adenosine infusion, (iii) before the sequential administrationof dipyridamole and adenosine (during the stabilization period), and(iv) during the 70 μg/kg/min adenosine infusion, subsequent todipyridamole bolus injection.

Results are given in Tables 3-6. Abbreviations used in the table aredefined below:

-   -   ADE: adenosine alone at 140 μg/kg/min    -   SC: sequential combination of dipyridamole followed by adenosine        at 70 μg/kg/min    -   PV: peak velocity (cm/sec)    -   MV: mean velocity (cm/sec)    -   max: velocity under stress conditions    -   min: velocity at rest (under basal conditions)    -   ( ): standard deviation    -   D %: velocity differential (peak or mean), as percentage of        maximum peak or mean velocity

Table 3 presents results comparing dipyridamole 28 μg/kg IV bolus (over20-30 seconds) followed by adenosine infusion at 70 μg/kg/min (“DIPS”sequential combination) as compared to adenosine infusion alone at thestandard single-agent dose of 140 μg/kg/min, in 30 patients.

TABLE 3 Peak velocity Peak velocity Mean velocity Mean velocity ADE SCADE SC Max Min Max Min Max Min Max Min Mean (s.d.) 82.6 30.6 81 30.661.4 23.1 60.2 22.9 (20.7) (8.5) (21) (9.6) (15.1) (6.1) (15.3) (7.3)Max velocity PV: 82.6 − 81 = 1.6 MV: 61.4 − 60.2 = 1.2 differential Maxvelocity 1.9% 1.9% differential (D %) P value 0.217 0.201

Table 4 presents results comparing dipyridamole (35 μg/kg) bolus(administered over 20-30 seconds), followed by adenosine, administeredby infusion at a rate of 70 μg/kg/min (“DIP4” sequential combination) ascompared to adenosine infusion alone at the standard single-agent doseof 140 μg/kg/min, in 5 patients.

TABLE 4 Peak velocity Peak velocity Mean velocity Mean velocity ADE SCADE SC Max Min Max Min Max Min Max Min Mean (s.d.) 80 28 78.8 28 60.422.2 57.8 23 (22.3) (7.4) (15.3) (7.7) (15.5) (5)  (14.4) (5.7) Maxvelocity PV: 80 − 78.8 = 1.2 MV: 60.4 − 57.8 = 2.6 differential Maxvelocity 1.5% 4.3% differential (D %) P value 0.863 0.448

Table 5 presents results comparing dipyridamole (23 μg/kg), administeredas a bolus over 20-30 seconds, followed by adenosine, administered byinfusion at a rate of 70 μg/kg/min (“DIP6” sequential combination) ascompared to adenosine infusion alone at the standard single-agent doseof 140 μg/kg/min, in 5 patients.

TABLE 5 Peak velocity Peak velocity Mean velocity Mean velocity ADE SCADE SC Max Min Max Min Max Min Max Min Mean (s.d.) 107 37.6 105.4 38.680.2 28.2 79.2 30 (36.5) (12.1) (34.3) (16.5) (25.4) (11.1) (24.2)(14.7) Max velocity PV: 107 − 105.4 = 1.6 MV: 80.2 − 79.2 = 1differential Max velocity 1.5% 1.2% differential (D %) P value 0.8420.771

Table 6 presents results cumulated from all 40 patients:

TABLE 6 Peak velocity Peak velocity Mean velocity Mean velocity ADE SCADE SC Max Min Max Min Max Min Max Min Mean (s.d.) 85.3 31.2 83.8 31.363.6 23.7 62.3 23.7 (24)   (9)  (23.3) (10.5) (17.3) (6.8) (17.3) (8.4)Max velocity PV: 85.3 − 83.8 = 1.5 MV: 63.6 − 62.3 = 1.3 differentialMax velocity 1.75% 2% differential (D %) P value 0.314 0.109

The measured blood flow velocities, whether peak or mean, were 3 to 4%lower, in absolute values, than those of adenosine alone (see Tables 3to 6). However, these differences were not statistically significant(all P values >0.05): there was no statistical difference between thestandard treatment—infusion of adenosine alone at 140 μg/kg/min—andsequential bolus administration of dipyridamole (at 4-6% its typicalsingle-agent total dose) followed by adenosine at 70 μg/kg/min, whetherassessed separately for each of the three tested dipyridamole doses(Tables 3-5), or cumulated across all dipyridamole doses (Table 6).

.Table 7 shows the number and frequency of occurrence among all 40patients of the three adverse events most commonly observed in clinicalpractice upon administration of adenosine alone at 140 μg/kg/min: chestpain, dyspnea, and flushing

TABLE 7 ADE All SC (DIP 4/5/6) # patients reporting # patients reportingAdverse event events (frequency) events (frequency) % reduction Chestpain  9 (22.5%)  5 (12.5%) −44% Dyspnea 20 (50%) 18 (45%) slightFlushing 21 (52.5%) 17 (42.5%) slight

Table 8 presents descriptive statistics and analysis of the mean globalvisual analogue scale (VAS) score for the three main adverse events(each one being scored from 0 to 10 with a total score of 30). VASscores provide a measure of patient self-assessment of painintensity/discomfort.

TABLE 8 n Mean SD Group DIP4 ADE 5 5.4 1.949 SC 5 3 3.742 Group DIP5 ADE30 5.95 3.705 SC 30 4.383 3.38 Group DIP6 ADE 5 8.2 1.095 SC 5 4.4 2.408

Although not tabulated in Table 8, the severity of the three mainadverse symptoms, cumulated across all dipyridamole doses, was reducedby 31.6% with the sequential combination as compared to adenosine alone.This decrease was statistically significant (p=0.001). No difference wasobserved as among the different doses of dipyridamole: all sequentialcombinations reduced mean severity on the VAS of each of the three mainadverse symptoms, as compared to adenosine alone at 140 μg/kg/min.

As shown in Table 7 the number (and frequency) of adverse events relatedto the stimulation of A1 receptors, mainly chest pain, was reduced by44% and its severity (not shown) decreased by 60% with the sequentialcombination treatment as compared to adenosine alone. The number (andfrequency) of adverse events related to the stimulation of A2areceptors, mainly dyspnea and flushing, did not decrease. However theirseverity (not shown) decreased by 24 and 38% respectively, with thesequential combination compared to adenosine alone.

The mean coronary flow reserve (ratio of maximal-stimulated coronaryblood flow “CBF” to baseline-resting CBF equivalent to peak and meanblood flow velocities ratios) of the 40 patients enrolled in the studywas above 2, which indicates that the observed reduction in side effectswith sequential treatment was drug dependent, and not flawed by theischemic status of the studied population.

Although not shown in the tabular data, EKG was not significantlydifferent with the sequential combination treatment as compared tostandard single-agent adenosine, and remained unchanged in all thepatients. Vital signs (heart rate, systolic and diastolic bloodpressures) changed similarly with the two methods. However, the heartrate increase and blood pressures decreases were less pronounced withthe sequential combination than with adenosine alone.

It should be noted that in the first series of 30 patients (DIP5 group),three (3) patients received the adenosine infusion 2 minutes after thedipyridamole bolus, and two (2) patients were injected the two agents(dipyridamole and adenosine) concurrently in the same infusion lineusing a “Y” connector. These two modalities appeared equally effectiveand as effective as the immediate sequential administration protocol.

In a first control experiment, 5 patients were treated according to amodification of the experimental protocol, in which the initialadenosine infusion at 140 μg/kg/min was followed by a five (5) minutestabilization period, and thereafter by a second, single-agent,adenosine infusion at 140 μg/kg/min, without the use of dipyridamole.Results are shown in Table 9. Abbreviations used in the table aredefined below:

-   -   PV: peak velocity (cm/sec)    -   MV: mean velocity (cm/sec)    -   max: velocity under stress conditions    -   min: velocity at rest (under basal conditions)    -   ADE1: first adenosine infusion    -   ADE2: second adenosine infusion

TABLE 9 PV-ADE1 PV-ADE2 MV-ADE1 MV-ADE2 Patient ID Max Min Max Min MaxMin Max Min MART 68 34 60 31 49 25 45 23 LIEN 65 23 66 22 48 17 48 16GRAND 102 30 103 29 75 22 75 22 NGHI 73 30 63 26 53 23 47 21 CORD 70 2862 25 50 20 48 20 Mean 75.6 29 70.8 26.6 55 21.4 52.6 20.4 Max PV: 75.6(ADE1) − 70.8 MV: 55 (ADE1) − 52.6 velocity (ADE2) = 4.8 (ADE2) = 2.4differ- ential P value 0.12 0.11

No statistically significant differences (P>0.05) were noted in velocitymeasurements as between first and second adenosine infusions. Nosignificant differences were noted in the occurrence of subjectivesymptoms (data not shown). These data confirm previous literaturereports that adenosine, administered acutely, does not inducetachyphylaxis. The data serve to validate the protocol design.

In a second set of control experiments, dipyridamole was administeredalone by bolus injection to 5 patients at the dosage of 28, 35 or 40μg/kg after a three minute adenosine infusion at 140 μg/kg/min, andagain after a 3 minute stabilization period. Data are shown in Table 10.

TABLE 10 DIP Symptoms Symptoms Patient dose PV-ADE PV-DIP MV-ADE MV-DIPunder under ID (μg/kg) Max Min Max Min Max Min Max Min ADE DIP aloneGROS 28 84 27 26 23 64 20 21 19 Flushing None 8/10 COCH 35 84 32 40 3061 23 28 22 Flushing None 6/10 WURI 35 88 25 23 21 71 21 20 18 None NoneSTUR 40 92 33 35 33 67 23 25 23 Dyspnea None 5/10 TALL 40 112 33 40 3486 25 29 24 None None

Dipyridamole did not modify peak and mean diastolic velocities. Nosymptoms were recorded during a follow-up of 10 minutes. The datademonstrate that intravenous bolus administration of dipyridamole as asingle agent in the dosage range used in the experimental protocol, hasno detectable effects; doses of dipyridamole at 28 to 40 μg/kg alone donot induce significant hemodynamic and clinical effects.

5.2 Example 2

A Phase II study was initiated to compare dipyridamole-adenosinecombination administration (also termed herein, at all doses,Adenosoft™) to adenosine alone (Adenoscan®, Astellas) as a pharmacologicstressor in coronary patients undergoing single photon emission computedtomography (SPECT) imaging studies. The study, which is ongoing, is amono-center, single-blind, 2-arm, cross-over trial.

All patients underwent a first SPECT imaging study using adenosine assingle agent pharmacologic stressor at 140 μg/kg/min, according tostandard clinical protocol. Only those patients in whom an ischemic zonewas detected were declared eligible for the second test, and wereenrolled in the study if other inclusion criteria were satisfied.

In the second test, eligible patients were stressed pharmacologically byeither bolus administration of dipyridamole over 20-30 seconds, followedby adenosine infusion at 70 μg/kg/min or their concurrentadministration. SPECT images were acquired as per the standard approachperformed the preceding week.

Randomization of SPECT images, and their analysis by two blindedreaders, took place every 10 patients. Anonymous and randomized imageswere assessed using the standard 17-segment model and thesemi-quantitative visual score method on a 5-point scale (from 0 to 4).Safety of the procedure was analyzed as in the preceding hemodynamicstudy (Example 1) using a visual scale, focusing on the three mostcommon symptoms seen with adenosine, as well as on EKG changes and otherusual cardiac parameters.

The study is on-going. It will include a total of about 60 patients.Preliminary results are as follows.

About 10 patients whose participation permitted the study protocoldetails to be finalized have been excluded from study statistics.However they provided the following information, summarized below.

The 70 μg/kg/min adenosine+28 μg/kg dipyridamole combination providedimages comparable to those provided by Adenoscan in 3 patients, butscored less well in two patients, at a level deemed unacceptableaccording to the study protocol. The 70 μg/kg/min adenosine+35 μg/kgdipyridamole combination provided images comparable to Adenoscan in 7consecutive patients, while under-scoring Adenoscan in one patient, butwithin the acceptable limits defined by the protocol.

In five patients of this initial series, adenosine and dipyridamole weremixed together before administration and infused over 4 minutes. Thismodality was successful in all the patients.

The combination stressor of 40 μg/kg dipyridamole and 70 μg/kg/minadenosine was tested and showed equivalent, and sometimes betterresults, than Adenoscan in terms of imaging efficacy in 19 patients (10sequential and 9 concurrent administrations). Table 11 shows the stressscores (correlated to ischemia defects) for the first 10 patients ofthis 40 μg/kg series (denominated, “Series I—sequential administration).

TABLE 11 Stress score A Stress score B Series I (Adenoscan) (SC) Deltascore Patient 1 5 4 1 Patient 2 13 11 2 Patient 3 5 5 0 Patient 4 4 4 0Patient 5 7 7.5 −0.5 Patient 6 5 5 0 Patient 7 4 3 1 Patient 8 14 14 0Patient 9 5 12.5 −7.5 Patient 10 5 6 −1 Total −5

The “stress score” is the image of ischemia in one or more of the 17cardiac segments, as scored from 0 to 4 by the blinded reader using thefollowing scale: normal perfusion=0, mild reduction in counts=1,moderate reduction in counts=2, severe reduction=3, absence ofuptake=4). Normally, a zone of ischemia is certain when a score ≧4 isnoted. A stress score sums the scores of all abnormal segments.

“Stress score A” is the image score difference between stress conditionsbetween adenosine alone and rest conditions. “Stress score B” is theimage score difference between stress conditions with the combinationstressor—dipyridamole bolus at 40 μg/kg over 20-30 seconds, followed byadenosine infusion at 70 μg/kg/min—and resting conditions. “Delta score”is the difference between “Stress score A” and “Stress score B.” It mustnot be >2

Since thallium is currently deemed the best isotope to test myocardialviability at rest, and sestamibi the best isotope to detect myocardialdefects under stress conditions, a dual isotope myocardial scintigraphytechnique was used for this study.

As seen from the data in Table 11, no patient had a delta score greaterthan 2: i.e., in no patient did the combination stressor performsignificantly worse as compared to Adenoscan. In three (3) patients, thedelta score was negative, indicating that the ischemic defects werebetter visualized with the combination stressor than with Adenoscanalone. Total delta score for the ten patients, which is the primarystudy end-point, is below 2 and even negative

The second 40 μg/kg series corresponding to the concurrentadministration of adenosine 70 μg/kg/min with dipyridamole 10 μg/kg/minis expected to provide similar results (a preliminary analysis made by atechnician who does not participate to the trial indicates that imagesare comparable in all the patients). However the randomized analysis ofthis series of images by the two blinded readers with correspondingdelta scores has not yet been performed (one patient missing to get to10).

With respect to patient tolerance of the procedure, initial results areshown in Table 12 (n=27 patients). Data from these initial resultsindicate that there is not much difference in symptomotology between (i)35 μg/kg dipyridamole combined with 70 μg/kg/min adenosine, and (ii) 40μg/kg of dipyridamole combined with 70 μg/kg/min adenosine. Results aretherefore cumulated, and include data from 8 patients treated with 35μg/kg dipyridamole plus adenosine at 70 μg/kg/min, and from 19 patientstreated with 40 μg/kg dipyridamole, plus adenosine at 70 μg/kg/min (SC).Given the similar adverse effect profile, the 40 μg/kg dipyridamole doseis currently preferred, since it tends to show greater efficacy. Asnoted above, all 27 patients were first imaged using Adenoscan alone(ADE).

TABLE 12 ADE SC (# patients reporting (# patients reporting Adverseevents event) event) % reduction Chest pain 14 8 −43% Dyspnea 11 9 NoneFlushing 14 14 None Note: Reduction in the number of chest pain eventsamong the patients (n = 19) who received dipyridamole 40 μg/kg withadenosine 70 μg/kg/mn was −45% with no difference regarding the numberof other adverse events. # = number of

Table 13 gives adverse event severity cumulated scores, evaluated on avisual scale (going from 0 to 10), for the first 27 patients.

TABLE 13 Chest pain Dyspnea Flushing Adenosine 60   40 43.5 Combination18.5 30 44.5 % Change −69% −25% +2.3% Note: % of changes among thepatients (n = 19) who received dipyridamole 40 μg/kg with adenosine 70μg/kg/mn were very similar to those of the table above

At this point in time, no difference in the occurrence of A₂receptor-related side effects, or severity of symptoms, has becomeclearly apparent as between the combination stressor and Adenoscan. Incontrast, the reduction in the occurrence (−43%) and severity (−69%) ofchest pain (an A₁ receptor-related adverse effect) has already becomemanifest in the first 27 patients. So too has reduction in ST changes onEKG, which are fewer and less severe during testing with the combinationas compared to Adenoscan: in 27 patients tested to date, only 6 patientshave ST variations. The difference in ST-variation for each patientalone is not significant, but the total difference has achievedsignificance, with a clear trend in favor of the combination. In thetable below (Table 14) ST-changes/baseline are expressed in millimeters.

TABLE 14 Patient ID Adenosine 140 μg/kg/mn Combination N^(o) 5 0.5 0N^(o)12 1 0.1 N^(o)14 0.8 0.3 N^(o)16 1 0.7 N^(o)17 1.2 0.9 N^(o)24 1 0Total 5.5 2

5.3 Example 3

A study was undertaken to assess pharmacological properties of apharmaceutical composition comprising adenosine and dipyridamole at anA:D weight ratio of 7:1. In particular, the study was conducted toassess the properties of a composition comprising adenosine at aconcentration of 7 mg/ml and dipyridamole at a concentration of 1 mg/ml.This particular formulation is very convenient, since it permits the useof plain figures for calculating concentrations, maximal volumes, andweights—which is useful to reduce dosing errors in the clinicalsetting—while also covering a wide range of needs, as shown in the tablebelow:

TABLE 15 Total Maximal amount of patient Adenosine adenosine per weightTotal amount concentration Volume unit covered of dipyridamole (mg/ml)(ml) (mg) (kgs) per unit (mg) 7 2 14 50 2 3 21 75 3 4 28 100 4 5 35 1255 6 42 150 6 8 56 200 8Dipyridamole is poorly soluble in saline and is unstable in the longterm in solvents at pH>4. Adenosine compositions currently used inclinical practice have pH>4, and are thus poorly suited to addition ofdipyridamole. Therefore, a more acidic pH was chosen. The lower pH alsoincreases adenosine solubility above 4 mg/ml, which is the upperacceptable adenosine concentration limit in saline.

The following composition was prepared:

TABLE 16 Final con- Component centration Supplier Reference Adenosine 7mg/ml Sigma Aldrich Eur. Ph. January 2005: 1486 Dipyridamole 1 mg/mlSigma Aldrich Eur. Ph. January 2005: 1199 Polyethyleneglycol 50 mg/ml SASOL Eur. Ph.. 600 January 2005: 1444 Tartaric acid 2 mg/ml SigmaAldrich Eur. Ph.. January 2005: 0460 Water for injection — (1 ml)Aguettant AMM: 319 508.5After sonication for 2 minutes and magnetic stirring for 10 minutes, thesolution became completely clear with a pH of 3.6 and an osmolality of151 mosmol/kg.

In summary, adenosine (Adenoscan, Astellas) is the standardpharmacological stressor used in cardiac imaging to induce near-maximalcoronary vasodilation. At its recommended dosage rate of 140 μg/kg/min,its use is attended by numerous uncomfortable side effects. The datafrom these studies demonstrate that the sequential bolus administrationof dipyridamole at 28-40 μg/kg—well below the total dose infused whendipyridamole is used as a single agent stressor—followed by infusion ofadenosine at 70 μg/kg/min, is equally efficacious in providing coronaryvasodilation for imaging studies, while causing fewer side effects. Thedata also demonstrate that dipyridamole and adenosine may be combined ina single infusion, over 4 minutes, to similar effect. Among the sideeffects reduced by the combination of the present invention are chestpain, and the risk of significant heart blockage.

All publications, patents, patent applications and other documents citedin this application are hereby incorporated by reference in theirentireties for all purposes to the same extent as if each individualpublication, patent, patent application or other document wereindividually indicated to be incorporated by reference for all purposes.

While various specific embodiments have been illustrated and described,it will be appreciated that various changes can be made withoutdeparting from the spirit and scope of the invention(s).

1. A pharmaceutical composition comprising adenosine and dipyridamole inan adenosine:dipyridamole weight ratio of about 2:1 to about 10:1. 2.The pharmaceutical composition according to claim 1, in which the ratiois about 2:1 to about 4:1.
 3. The pharmaceutical composition accordingto claim 1, in which the ratio is about 7:1.
 4. The pharmaceuticalcomposition according to claim 1, in which the ratio is about 8:1. 5.The pharmaceutical composition according to claim 1, wherein adenosineand dipyridamole are present in amounts that permit adenosine to beadministered at a dosage rate of 35 to 100 μg/kg/min and dipyridamole tobe administered at a dosage rate of 3.5 to 50 μg/kg/min.
 6. Thepharmaceutical composition of claim 5, wherein the composition is asterile fluid.
 7. The pharmaceutical composition of claim 6, whereinadenosine and dipyridamole are present at concentrations that permitdirect intravenous administration.
 8. The pharmaceutical compositionaccording to claim 6 or claim 7, wherein adenosine and dipyridamole arepresent at concentrations that permit administration of adenosine at adosage rate of 70 μg/kg/min and dipyridamole at a dosage rate of 8.75 to10 μg/kg/min.
 9. The pharmaceutical composition according to claim 6 orclaim 7, wherein adenosine and dipyridamole are present atconcentrations that permit administration of adenosine at a dosage rateof 50 μg/kg/min and dipyridamole at a dosage rate of 12.5 to 25μg/kg/min.
 10. The pharmaceutical composition according to claim 6,wherein the concentration of adenosine is about 1 to 10 mg/ml.
 11. Thepharmaceutical composition according to claim 10, wherein theconcentration of adenosine is about 3 mg/ml.
 12. The pharmaceuticalcomposition according to claim 10, wherein the concentration ofadenosine is about 4 mg/ml.
 13. The pharmaceutical composition accordingto claim 10, wherein the concentration of adenosine is about 5 mg/ml.14. The pharmaceutical composition according to claim 10, wherein theconcentration of adenosine is about 7 mg/ml.
 15. The pharmaceuticalcomposition according to claim 6, wherein the concentration ofdipyridamole is about 0.1 to 5 mg/ml.
 16. The pharmaceutical compositionaccording to claim 15, wherein the concentration of dipyridamole isabout 0.375 to 0.428 mg/ml.
 17. The pharmaceutical composition accordingto claim 15, wherein the concentration of dipyridamole is about 0.5 to0.571 mg/ml.
 18. The pharmaceutical composition according to claim 15,wherein the concentration of dipyridamole is about 0.625 to 0.714 mg/ml.19. The pharmaceutical composition according to claim 15, wherein theconcentration of dipyridamole is about 0.75 to 0.857 mg/ml.
 20. Thepharmaceutical composition according to claim 15, wherein theconcentration of dipyridamole is about 0.875 to 1 mg/ml.
 21. Thepharmaceutical composition according to claim 15, wherein theconcentration of dipyridamole is 1 mg/ml.
 22. A unit dose containingabout 2 to 50 ml of the composition according to claim 1, wherein thecomposition is a sterile fluid.
 23. The unit dose of claim 22 containingabout 2 ml.
 24. The unit dose of claim 22 containing about 3 ml.
 25. Theunit dose of claim 22 containing about 4 ml.
 26. The unit dose of claim22 containing about 5 ml.
 27. The unit dose of claim 22 containing about7 ml.
 28. The unit dose of claim 22 containing about 8 ml.
 29. The unitdose of claim 22 containing about 14 ml.
 30. A unit dose containingabout 5 to 60 mg of adenosine and about 0.5 to 30 mg of dipyridamole,wherein the composition is a solid capable of sterile reconstitution ina physiologically acceptable solvent or solution.
 31. The unit dose ofclaim 30 containing about 21 mg of adenosine and about 3 mg ofdipyridamole.
 32. The unit dose of claim 30 containing about 28 mg ofadenosine and about 4 mg of dipyridamole.
 33. The unit dose of claim 30containing about 35 mg of adenosine and about 5 mg of dipyridamole. 34.The unit dose of claim 30, containing about 42 mg of adenosine and about6 mg of dipyridamole
 35. The unit dose of claim 30 containing about 56mg of adenosine and about 8 mg of dipyridamole
 36. The unit dose ofclaim 30 containing about 20 mg of adenosine and about 5 to 10 mg ofdipyridamole.
 37. The unit dose of claim 30 containing about 30 mg ofadenosine and about 7.5 to 15 mg of dipyridamole.
 38. The unit dose ofclaim 30 containing about 40 mg of adenosine and about 10 to 20 mg ofdipyridamole. 39-58. (canceled)
 59. A kit comprising at least one unitdose of dipyridamole and at least one unit dose of adenosine. 60-115.(canceled)